Method of introducing liquid quench into a carbon black reactor

ABSTRACT

Method of introducing a liquid quench into a carbon black reactor to reduce the temperature of the gaseous effluent wherein a gaseous fluid such as steam, nitrogen, or carbon dioxide is used to increase the pressure on the liquid quench and facilitate the dispersal thereof in the gaseous effluent. The method is particularly useful for quenching hot gases in a carbon black reactor in standby operation.

United States Patent Thomas 1 Jan. 25, 1972 [54] METHOD OF INTRODUCINGLIQUID QUENCH INTO A CARBON BLACK REACTOR [72] Inventor: Warren M.Thomas, Bartles ville, Okla. [73] Assignee: Phillips Petroleum Company[22] Filed: July 18, 1969 [2]] Appl. No.1 842,960

52 US. Cl ..23/209.4, 23/2096, 23/2595, 23/277, 239/1, 261 /l 51 .C09c1/50 260/679; 261/1, DIG. 9; 165/1, 32, 38; 239/1 PrimaryExaminer-Edward J. Meros Attorney-Young and Quigg [57] ABSTRACT Methodof introducing a liquid quench into a carbon black reactor to reduce thetemperature of the gaseous effluent wherein a gaseous fluid such assteam, nitrogen, Or carbon dioxide is used to increase the pressure onthe liquid quench and facilitate the dispersal thereof in the gaseouseffluent. The method is particularly useful for quenching hot gases in acarbon black reactor in standby Operation.

7 Claims, 1 Drawing Figure METHOD OF INTRODUCING LIQUID QUENCII INTO ACARBON BLACK REACTOR This invention relates to carbon black.

In one of its more specific aspects, this invention relates to quenchingthe smoke produced in a carbon black reactor.

Furnace carbon black is conventionally produced as a suspension ofparticles in the product gases from the pyrolytic decomposition of ahydrocarbon in the presence of a fuel, the gaseous suspension beingknown as smoke. At some point within the reactor, the smoke is generallyquenched, either for the purpose of slowing down the reaction or for thepurpose of terminating it. That material with which the smoke isquenched is generally water. Even and rapid distribution of the quenchin the reactor is important, not only from the standpoint of terminatingthe reaction, but also from the standpoint of preventing any portion ofthe quench from flowing as an unvaporized stream through the reactor andits outlet conduit and creating localized thermal stresses and shockproblems.

Frequently, when a reactor is temporarily removed from operation, it ismaintained in standby condition by continuing to charge to it a smallquantity of fuel. In this instance, no carbon black is produced, but hotgases are still emitted from the reactor and are routed to disposalthrough the outletconduit. However, it is still desirable to quenchthese gases at the outlet of the reactor in order to protect thenoninsulated conduit downstream of the reactor from high temperatures.Since standby operation produces reduced quantities of effluent gases,quench requirements are low and the discharge pressure of those nozzleswhich discharge the quench into the reactor is considerably reduced fromthat operation in which carbon black is produced, with the result thatthe quench is not adequately distributed within the reactor and thepreviously mentioned problems arise. The method of this invention solvesthose problems.

According to this invention, there is provided a method of introducing aliquid quench into a carbon black reactor to reduce the temperature ofthe hot gases emitted therefrom which comprises introducing a gaseousfluid in combination with the liquid quench through dispersal means intothe hot gases within the reactor to facilitate the dispersal of theliquid quench in the hot gases.

The method of this invention will be more easily understood whenexplained in conjunction with the attached drawing which illustrates oneof the embodiments of this invention.

Referring now to the attached drawing, there is shown the quench section2 of carbon black reactor 1, the upstream portion of the reactor notbeing shown. Carbon black is discharged from quench section 2 throughoutlet conduit 3 to subsequent recovery facilities.

Quench section 2 is equipped with quench introductory points 4 and 5,nozzles generally being employed at these points. In both instances, anynumber of points can be employed and optionally positioned in zone 2.From water header 8, water conduit 6 leads to quench points 4 and waterconduit 7 leads to quench introductory points 5.

During the production of carbon black, it is conventional to measure thetemperature in the outlet conduit 3 at point 9 and to regulate thequantity of water introduced through main header 8 by means of controlvalve 19 to produce the desired temperature at point 9.

Generally, water is introduced into the reactor at some predeterminedpressure, for example, 125 p.s.i.g. Under standby operation, the rate ofquench flow decreases and, accordingly, the pressure on the quenchintroductory points 4 and decreases such that the nozzles at thesepoints lose their ability to produce a spray of liquid quench readilyentrainable in the hot gases passing through zone 2. As a result, thequench system becomes less effective with quantities of the unvaporizedquench often entering the outlet conduit 3.

In order to overcome this difficulty, steam is introduced during periodsof reduced operation from header 10 into conduit 6 through conduit 12and into conduit 7 through conduit 11. This steam is provided at anypressure greater than that normal quench pressure in conduits 6 and 7.In steam header I0. there is installed pressure control valve [4. It isoperated by pressure sensing point IS in open communication with conduit10. As a result, pressure sensing point I5 senses a pressure equivalentto that in quench conduits 6 and 7 and opens and closes in responsethereto in order to maintain the pressure in these conduits at aprearranged value. For example, if the pressure in steamheader 10 is ISOp.s.i.g. and a pressure of I00 p.s.i.g. is desired in conduits 6 and 7for satisfactory introduction of quench into points '4 and 5, anddecreasing the rate through, lines 6 and 7 lowers the pressure thereinto 65 p.s.i.g., this reduced pressure, as sensed by point 15, opensvalve 14 with the result that steam is introduced through conduits I1and 12 in sufficient quantityto return the operating pressure inconduits 6 and 7 and at quench introductory points 4 and 5 to l00p.s.i.g.

The effect of introducing the steam is twofold. Not only does it bringthe pressure in the quench lines to more desirable values, but the steamtends to atomize the quench upon emission from the nozzles and sofacilitates the vaporization of the quench in the smoke, thuseliminating the likelihood of free water in the subsequent conduit.

It will be appreciated that while the subject invention has beenexpressed in terms of steam, it is possible to employ other fluids inthe same manner. For example, it is possible to employ any suitable gas,such as nitrogen, carbon dioxide and the like. It is only required thatthe medium employed be of such pressure as to bring the quench materialup to that pressure at which the nozzles operate most efficiently.

Similarly, it may be desired to supply steam to only one set of nozzlesrather than to a plurality of sets of nozzles inasmuch as thetemperature at the foremost nozzles is higher and, hence, vaporizationof the spray from these nozzles is likely to be more easilyaccomplished.

The following is an example of the operation of this system.

A carbon black reactor was placed on standby operation under conditionsat which the quantity of low pressure quench water introduced was 2,300lb./hr. About 960 lb./h r. of unvaporized water was collected from theoutlet conduit. The outlet conduit temperature had been reduced to about600 F.

Under the method of this invention, 400 lb. of quench water per hourwere employed with 254 lb./hr. of steam, this total of 654 lb./hr. beingintroduced through quench points 4 and 5. The conduit outlet temperaturewas about 600 F. and no water was collectable from the outlet conduit.

From these tests it will be seen that while comparable outlettemperatures were attained under both methods, in the former thetemperatures were not uniform within the system as evidenced by thepresence of the unvaporized water. In contrast, in the latter method allwater was vaporized and the previously encountered stresses wereavoided.

Any suitable nozzles can be employed in the practice of this invention.Similarly, this invention can be employed to improve the operation ofthe quench nozzles and of prequench nozzles.

It will be appreciated that various modifications can be made to thescope of the invention as disclosed herein and that the method of thisinvention can be applied to the carbon black process wherein thesmokeproduct, itself, is quenched. Such, however, are considered asbeing within the scope of this invention.

What is claimed is: r

I. A method of introducing a liquid quench into a carbon black reactorto reduce the temperature of the hot gases emitted therefrom whichcomprises dispersing a gaseous fluid in combination with said liquidquench into said hot gases, said gaseous fluid being introduced in aquantity and at a pressure sufficient to raise the pressure on saidliquid quench and facilitate the dispersal of said liquid quench in saidhot gases.

2. The method defined in claim 1 in which the liquid quench is water andthe gaseous fluid is steam.

3. The method defined in claim] in which the gaseous fluid is selectedfrom the group consisting of steam, nitrogen and carbon dioxide.

the product of oxidation of a fuel.

7. The method of claim I in which said gaseous fluid is introduced intosaid reactor at a plurality of points less in number than the pluralityof points at which said liquid quench is introduced into said reactor.

4i l t

2. The method defined in claim 1 in which the liquid quench is water andthe gaseous fluid is steam.
 3. The method defined in claim 1 in whichthe gaseous fluid is selected from the group consisting of steam,nitrogen and carbon dioxide.
 4. The method defined in claim 1 in whichthe gaseous fluid and liquid quench are introduced into said reactor ata plurality of points.
 5. The method of claim 1 in which said gaseousfluid and said liquid quench are introduced during standby conditions.6. The method of claim 1 in which said hot gases comprise the product ofoxidation of a fuel.
 7. The method of claim 1 in which said gaseousfluid is introduced into said reactor at a plurality of points less innumber than the plurality of points at which said liquid quench isintroduced into said reactor.